Xo. 481] 



VOLOX FOR LABORATORY USE 



food supply and poor light, but found it impossil) 

 either so that they would live for more than four d; 

 experience has convinced me that in our laborato 

 principal causes of the death of the organism has I 

 mineral substances in the tap water in which the s| 

 kept. 



In collecting Volvox for our laboratorv it Iia> Ix t ii 

 bring in considerable quantitio of vcwctjihlc matcri; 

 Riccia, etc.) from the ponds in wliicli X'olvo.x occiirr 

 a little water, and place this material in shallow glas 

 with tap water. As fast as the organisms gathered 

 side of the dish they were picked off and removed to ; 

 tap water, it being deemed unsafe to leave them ii 

 dish exposed to the attacks of crustaceans. Su- 

 deleterious substances in the tap water, as well as 

 proper food supply, caused the death of the oriraiiisii 

 attempt to reproduce the natural couilitioii-. Wat- 

 Volvox was brought in in consiflcrahic (|uantinc>, to 

 small amount of the vegetai)l<' niatcriai. and place 

 glass dishes without the addition of tap uatci'. Tli 



loss of water by eva|)orati()n and to k<'e|> out Itactrr' 

 except that when exj)osed to direct >unliulit it wa-- t'o - 



to prevent a rise of temperature Ih-voikI tlic optiinuni. 

 was not changed at any time during- the cour>e of th - 

 in the majority of the atpiaria thus prepared. \'o|vo\ 

 several weeks; in the fall of !!•().">. I'olro.r (inn tis \va> 

 several aquaria for from foiu- t(» ei<:ht week^; le>- 

 attained with Volro.v (jhihafor in the >{)ri 



It was noted that I'niro.r (/Inhator chi-ters about de 

 larvie, perhaps on account of the presence of car 

 A moderate amoinit of decayiui;' plant or 

 water seems to be one of the essential c<»n 

 In its natural environment. N'olvox i> ot 

 stagnant water. 



